Summer Wars (2009) is a Animation, Science Fiction film that follows teenage math whiz Kenji Koiso agrees to take a summer job at the Nagano hometown of his crush, Natsuki. When he arrives, he finds that her family have reunited to celebrate the 90th birthday of their matriarch. His job: pretend to be Natsuki's fiancé. Meanwhile, his attempt to solve a mathematical equation causes a parallel world's collision with Earth. Currently, you can watch Summer Wars on HBO Max Amazon Channel, YouTube TV, HBO Max, Amazon Video. Streaming availability may vary by country and platform over time. It has a user rating of 7.5 out of 10 from 1,050 votes. Fans of animation movies may also want to explore similar titles below.